(function(win, lib) {
  var doc = win.document;
  var docEl = doc.documentElement;
  var metaEl = doc.querySelector('meta[name="viewport"]');
  var flexibleEl = doc.querySelector('meta[name="flexible"]');
  var dpr = 0;
  var scale = 0;
  var tid;
  var flexible = lib.flexible || (lib.flexible = {});

  if (metaEl) {
    console.warn('将根据已有的meta标签来设置缩放比例');
    var match = metaEl.getAttribute('content').match(/initial\-scale=([\d\.]+)/);
    if (match) {
      scale = parseFloat(match[1]);
      dpr = parseInt(1 / scale);
    }
  } else if (flexibleEl) {
    var content = flexibleEl.getAttribute('content');
    if (content) {
      var initialDpr = content.match(/initial\-dpr=([\d\.]+)/);
      var maximumDpr = content.match(/maximum\-dpr=([\d\.]+)/);
      if (initialDpr) {
        dpr = parseFloat(initialDpr[1]);
        scale = parseFloat((1 / dpr).toFixed(2));
      }
      if (maximumDpr) {
        dpr = parseFloat(maximumDpr[1]);
        scale = parseFloat((1 / dpr).toFixed(2));
      }
    }
  }
  if (!dpr && !scale) {
    var isAndroid = win.navigator.appVersion.match(/android/gi);
    var isIPhone = win.navigator.appVersion.match(/iphone/gi);
    var devicePixelRatio = win.devicePixelRatio;
    if (isIPhone) {
      // iOS下，对于2和3的屏，用2倍的方案，其余的用1倍方案
      if (devicePixelRatio >= 3 && (!dpr || dpr >= 3)) {
        dpr = 3;
      } else if (devicePixelRatio >= 2 && (!dpr || dpr >= 2)) {
        dpr = 2;
      } else {
        dpr = 1;
      }
    } else {
      // 其他设备下，仍旧使用1倍的方案
      dpr = 1;
    }
    scale = 1 / dpr;
  }
  docEl.setAttribute('data-dpr', dpr);
  if (!metaEl) {
    metaEl = doc.createElement('meta');
    metaEl.setAttribute('name', 'viewport');
    metaEl.setAttribute('content', 'initial-scale=' + scale + ', maximum-scale=' + scale + ', minimum-scale=' + scale +
      ', user-scalable=no');
    if (docEl.firstElementChild) {
      docEl.firstElementChild.appendChild(metaEl);
    } else {
      var wrap = doc.createElement('div');
      wrap.appendChild(metaEl);
      doc.write(wrap.innerHTML);
    }
  }

// 修改
var browser = {
  versions:function(){
    var u = navigator.userAgent,
        app = navigator.appVersion;
        return{
          trident: u.indexOf('Trident') > -1,   //IE内核
          presto: u.indexOf('Presto') > -1,   //opera内核
          webKit: u.indexOf('AppleWebKit') > -1,   //苹果、谷歌内核
          gecko: u.indexOf('Gecko') > -1 && u.indexOf('KHTML') == -1,   //火狐内核
          mobile: !!u.match(/App LeWebKit.*Mobile.*/),   //是否为移动终端
          ios: !!u.match(/\(i[^;]+;( U;)? CPU.+Mac 0S X/),   //ios终端
          android: u.indexOf('Android') > -1 || u.indexOf('Linux') >-1, //android终端或者uc浏览器
          iPhone: u.indexOf('iPhone') > -1,   //是否为iPhone
          iPad: u.indexOf('iPad') > -1,   //是否为iPad
        }
  }(),
  language:(navigator.browserLanguage || navigator.language).toLowerCase()
}
// 修改

  function refreshRem() {
    var width = docEl.getBoundingClientRect().width;
    if(!browser.versions.mobile){
      width = width > 1200 ? width : 1200
    }
    var rem;
    if (width / dpr > 540) {
      width = width * dpr;
    }
    // var rem = width / 10;
    if(browser.versions.mobile){
      rem = width / 7.5
      console.log('移动端尺寸 750px', rem);
    }else{
      rem = width / 19.2
      console.log('PC端尺寸 1920px', rem);
    }
    docEl.style.fontSize = rem + 'px';
    flexible.rem = win.rem = rem;
  }
  win.addEventListener('resize', function() {
    clearTimeout(tid);
    tid = setTimeout(refreshRem, 300);
  }, false);
  win.addEventListener('pageshow', function(e) {
    if (e.persisted) {
      clearTimeout(tid);
      tid = setTimeout(refreshRem, 300);
    }
  }, false);
  if (doc.readyState === 'complete') {
    doc.body.style.fontSize = 12 * dpr + 'px';
  } else {
    doc.addEventListener('DOMContentLoaded', function(e) {
      doc.body.style.fontSize = 12 * dpr + 'px';
    }, false);
  }

  refreshRem();
  flexible.dpr = win.dpr = dpr;
  flexible.refreshRem = refreshRem;
  flexible.rem2px = function(d) {
    var val = parseFloat(d) * this.rem;
    if (typeof d === 'string' && d.match(/rem$/)) {
      val += 'px';
    }
    return val;
  }
  flexible.px2rem = function(d) {
    var val = parseFloat(d) / this.rem;
    if (typeof d === 'string' && d.match(/px$/)) {
      val += 'rem';
    }
    return val;
  }
})(window, window['lib'] || (window['lib'] = {}));
